Van heater (driving heater) issues

[sbmcd]

Hi, my van seems to have developed a problem with the driving heater, when the heater control is set at 22 deg, in the middle of the range at TDC, the van produces the temperature I would expect when it is warming up, however once the van is up to full temperature it starts to cool down to a point that the heater control has to be almost at full heat before I get any warm air.

VW have reset the heater servos but that has not helped.

My feeling is that there is an issue with the thermostat somewhere in the cooling system, anyone else had this problem? any one have a diagram of the water / heater circuit?

Heating system is standard, not climatronic.

 

[snowy55]

What does the temperature gauge in the speedo read?

 

[sbmcd]

What does the temperature gauge in the speedo read?

About 100 I think, temperature remains constant regardless of demand by heater, that was what I checked once the problem occurred. Is there only one thermostat?

 

[snowy55]

If the main engine temperature is correct then there must be some other temperature control device, either another water tstat for the heater water (not likely ) or a device that blends hot and cold air (more likely ) that is controlled by a sensor.
Sorry I'm not being much help.
Like you say you need a diagram.

 

[Loz]

Assuming there is no airlock in the coolant there is a servo air blending flap (you say has been checked) and also a temperature sensor on the heater.


diagramme for a 2014 vehicle (not sure from your details)

 

[sbmcd]

Assuming there is no airlock in the coolant there is a servo air blending flap (you say has been checked) and also a temperature sensor on the heater.
View attachment 15680

diagramme for a 2014 vehicle (not sure from your details)

My van is 2014 thanks, it is strange that it works ok when van is warming up, heater and engine water circuit only open, but when main stat opens the main radiator the problem manifests itself. that is what led me to think it was not the heater air mixer servo.

 

[Tommy Gun]

Hi,

I had exactly the same issue on a previous car, a Skoda 1.9TDi 4x4.
After 2 or 3 trips to the garage, the problem never did get resolved unfortunately. What I did notice was that it only did it when the air-con was on. Is it doing it with both air-con on & off? If it's doing it under the same circumstances as mine was, then it might help someone on here trace the problem a bit quicker. Sorry I can't help with this, but thought the above might be worth a punt.

Hope you get it sorted.

Cheers
Tom

 

[sbmcd]

Had the van into VW Edinburgh, they replaced the heater flap servo motor under warranty, whole dash had to come out, it was in for two days.

Now working as it should.

 

[sidepod]

I believe Initial warm up is quick due to air being pumped around exhaust cats. This helps achieve emision targets by reducing cold start phase time.

Once up to temp it's a different story.
It's nothing silly like the knob installed part way around the spigot meaning what looks like a given setting is actually several degrees (rotation) different.

 

[sbmcd]

Hi, my van seems to have developed a problem with the driving heater, when the heater control is set at 22 deg, in the middle of the range at TDC, the van produces the temperature I would expect when it is warming up, however once the van is up to full temperature it starts to cool down to a point that the heater control has to be almost at full heat before I get any warm air.

VW have reset the heater servos but that has not helped.

My feeling is that there is an issue with the thermostat somewhere in the cooling system, anyone else had this problem? any one have a diagram of the water / heater circuit?

Heating system is standard, not climatronic.

How can steverjones disagree with this??

 

[sbmcd]

I believe Initial warm up is quick due to air being pumped around exhaust cats. This helps achieve emision targets by reducing cold start phase time.

Once up to temp it's a different story.
It's nothing silly like the knob installed part way around the spigot meaning what looks like a given setting is actually several degrees (rotation) different.

Thanks now fixed, see above.

 

[andybalman]

the passenger side of my T5 is not getting any heat at all. My usual mechanic says there are a number of motors that could have gone wrong but its a big job as the dash has to come out to investigate. VW dealer wants £45 just to investigate before he will quote........ Any easy solutions or should I just buy a warm blanket for the passenger?

 

[WelshGas]

How can steverjones disagree with this??

It is so annoying, and I think very rude, to click " Disagree " without giving a reason or a comment.

 

[sbmcd]

Just back from 5 weeks in Europe with our van, cold on our return today and It turns out the heating problem I had has not been resolved by replacement of the heater servo motor. Still seems to work ok while the engine is warming up but once up to full temp heater runs cold unless turned 3/4 full heat, still think it could be a thermostat issue. Booked in again next week, third time, will keep you posted.

 

[WelshGas]

To be expected. A Forum, especially a Technical Forum and Thread as this is, depends on Members Helping each other. Clicking on " Disagree " without an explanation is not helpful.


In the NON-Technical Forums it is acceptable.

 

[Buds]

Looking for some advice on the Driving heater.
When I have the driving heater set to off there is still heat coming out of the vents and even when I vent them to the 0 position a small amount of heat comes through. Doesn’t seem to be right that heat is always flowing through?
thanks
Jan

 

[GrumpyGranddad]

Looking for some advice on the Driving heater.
When I have the driving heater set to off there is still heat coming out of the vents and even when I vent them to the 0 position a small amount of heat comes through. Doesn’t seem to be right that heat is always flowing through?
thanks
Jan

I’ve also noticed this. Seems to be when the outside temperature is below the minimum heater setting (16 degees) Our van is in for it’s first service next week and i’ll mention it.

 

[GrumpyGranddad]

Looking for some advice on the Driving heater.
When I have the driving heater set to off there is still heat coming out of the vents and even when I vent them to the 0 position a small amount of heat comes through. Doesn’t seem to be right that heat is always flowing through?
thanks
Jan

Had the opposite today @Buds . Had cool air coming out of the outermost vents even when turned the heater up to it’s maximum!?

 

[Buds]

Had the opposite today @Buds . Had cool air coming out of the outermost vents even when turned the heater up to it’s maximum!?

Crazy GG !!

On our way back from Llandudno yesterday lunch time it was 17 degrees and it was blasting out and had to open both front windows, surely that can’t be right !!

Be interested to know what your garage responds with GG.

 

[Amarillo]

Crazy GG !!

On our way back from Llandudno yesterday lunch time it was 17 degrees and it was blasting out and had to open both front windows, surely that can’t be right !!

Be interested to know what your garage responds with GG.

When I had a similar problem - warm air blasting out in summer when temp was set at 18 - it turned out (after checking the parking heater was off) that one of the two little critters which infest my rear seats, had turned the rear thermostat up to max.

So maybe, before a visit to the garage, you test this hasn’t happened to you by pressing the sync button on the Climotronic controls.

 

[GrumpyGranddad]

Thanks @Amarillo i’ll check that shortly but since my van has a ‘synchronise’ function for the heating ‘zones’ i’d be surprised.

 

[Amarillo]

Thanks @Amarillo i’ll check that shortly but since my van has a ‘synchronise’ function for the heating ‘zones’ i’d be surprised.

One of the more serious flaws of the climatronic design is there is no lock button to the synchronise function and rear passengers can override the driver at will.

Whichever rear seat passenger is next to the controls can use it as a means to wind up the other rear passenger.

E.g.1. Rear passenger 2, “I’m hot”.
Rear passenger 1 turns heat to boil.

E.g.2. Rear passenger 2, “I’m cold”.
Rear passenger 1 turns heat to freeze.

In both examples the driver can set the temperature to the same as the driver by pressing the sync button, or a temp of the driver’s choice for the rear by pressing ‘rear’ then spinning the dial, but passenger 1 can spin their dial to boil or freeze depending on what passenger 2 would find least desirable, immediately overriding the driver.

 

[GrumpyGranddad]

One of the more serious flaws of the climatronic design is there is no lock button to the synchronise function and rear passengers can override the driver at will.

Whichever rear seat passenger is next to the controls can use it as a means to wind up the other rear passenger.

E.g.1. Rear passenger 2, “I’m hot”.
Rear passenger 1 turns heat to boil.

E.g.2. Rear passenger 2, “I’m cold”.
Rear passenger 1 turns heat to freeze.

In both examples the driver can set the temperature to the same as the driver by pressing the sync button, or a temp of the driver’s choice for the rear by pressing ‘rear’ then spinning the dial, but passenger 1 can spin their dial to boil or freeze depending on what passenger 2 would find least desirable, immediately overriding the driver.

But would changing the rear affect the temperature selected at the front? My problem yesterday was that after turning the heat up to HI I got cold air from the outermost front vents. The opposite happened recently when I had the temperature set to LO and I had warm air from the outermost vents. It’s in for it’s 1st service tomorrow so will mention it. Might be ‘user error’ but don’t think so.

 

[Amarillo]

But would changing the rear affect the temperature selected at the front? My problem yesterday was that after turning the heat up to HI I got cold air from the outermost front vents. The opposite happened recently when I had the temperature set to LO and I had warm air from the outermost vents. It’s in for it’s 1st service tomorrow so will mention it. Might be ‘user error’ but don’t think so.

It does seem odd.

All I can advise are things to check. It can be difficult to determine where drafts are blowing from. Once I was convinced warm air was coming from the parking heater when it was coming from the rear vents. But maybe it’s just me.

 

[GrumpyGranddad]

It does seem odd.

All I can advise are things to check. It can be difficult to determine where drafts are blowing from. Once I was convinced warm air was coming from the parking heater when it was coming from the rear vents. But maybe it’s just me.

Thanks but definitely coming from front vents. I’m just wondering if the Climate Control software is to blame. I.e. it mixes warm and cool air in the cabin via different vents to achieve the right temperature rather than ‘pre-mix’ it and distribute through all vents simultaneously? I’ll see what Citygate say tomorrow.